Physiological performance predictors in mountain bike multi-stage races.

BACKGROUND: This study set out to identify physiological variables that may predict performance in The Cape Epic, an 8-day multi-stage mountain bike (MTB) race held annually in South Africa.

METHODS: Twenty-four amateur riders underwent VO2max testing within the 8 weeks prior to the event. Blood lactate measurements were taken to determine the power output corresponding to a fixed lactate concentration of 2 (LT2) and 4 mmol/L (OBLA) during the incremental test. Total race time was selected as dependent variable.

RESULTS: Absolute power output at LT2 (POLT2) had the strongest correlation (r=-0.80; CI: -0.91 to -0.59) with total race time. In general, absolute physiological variables, compared with relative values, correlated more favorably with total race time, suggesting that body mass may be of lesser importance in these longer events. Relative correlations were stronger when normalized to an exponent of 0.79. The correlations for VO2max and end maximal lactate with total race time were negligible (r=-0.14, CI: -0.51 to 0.28); r=0.03, CI: -0.32 to 0.43).

CONCLUSIONS: The findings of this study emphasize the importance of a well-developed aerobic system in multi-day MTB stage races and that riders should focus on developing a high sustainable sub maximal power output in order to complete the race in the shortest possible time.